add basic bootstrap for coverage

bootstrap/remove_orphaned_pycs.py

Index: bootstrap/remove_orphaned_pycs.py
diff --git a/bootstrap/remove_orphaned_pycs.py b/bootstrap/remove_orphaned_pycs.py
new file mode 100755
index 0000000000000000000000000000000000000000..e9661a8c90518543c6212b5391d496bb741a4f35
--- /dev/null
+++ b/bootstrap/remove_orphaned_pycs.py
@@ -0,0 +1,33 @@
+#!/usr/bin/env python
+# Copyright 2016 The LUCI Authors. All rights reserved.
+# Use of this source code is governed under the Apache License, Version 2.0
+# that can be found in the LICENSE file.
+
+import logging
+import os
+import sys
+
+
+def main(argv):
+  logging.basicConfig(level=logging.INFO)
+  if len(argv) == 0:
+    bootstrap_dir = os.path.dirname(os.path.abspath(__file__))
+    infra_dir = os.path.dirname(bootstrap_dir)
+    argv = [infra_dir]
+
+  for root in argv:
+    # This could take an argument, except gclient DEPS has no good way to pass
+    # us an argument, and gclient getcwd() is ../ from our .gclient file. :(
+    logging.debug("Cleaning orphaned *.pyc files from: %s" % root)
+
+    for (dirpath, _, filenames) in os.walk(root):
+      fnset = set(filenames)
+      for filename in filenames:
+        if filename.endswith(".pyc") and filename[:-1] not in fnset:
+          path = os.path.join(dirpath, filename)
+          logging.info("Deleting orphan *.pyc file: %s" % path)
+          os.remove(path)
+
+
+if __name__ == '__main__':
+  sys.exit(main(sys.argv[1:]))